14 documents found, page 1 of 2
Microfabrication of rubidium-85 vapor cell for optically pumped magnetometer ap...
Pereira, Hugo Martins; Dores, B. S.; Silva, J. P. O.; Venâncio, Armando; Cerqueira, M. F.; Rodrigues, J. A.; Correia, J. H.Neuroimaging methods have contributed to enhancing the knowledge of human brain activity. Magnetoencephalography is a general neuroimaging method that typically uses superconducting quantum interference devices as brain magnetic field sensors that require cryogenic cooling, putting practical and economical limitations. Optically pumped magnetometers are a promising alternative based on the use of atomic vapor c...
Special Focus on Advances in Symbolic and Numeric Computation IV
Loja, M.A.R.; Bezzeghoud, M.; Barbosa, J. I.; Rodrigues, J. A.This Special Focus on Advances in Symbolic and Numeric Computation IV of Mathematics in Computer Science (MCS) edited by Amélia Loja, Mourad Bezzeghoud, Joaquim Infante Barbosa and José Alberto Rodrigues is organized in connection with the 5th International Conference on Numerical and Symbolic Computation: Developments and Applications, and it is devoted to publishing relevant results on the development and/or ...
Mems-based fabrication of an atomic vapor cell for brain magnetic field measure...
Pereira, H. M.; Vieira, J. N.; Vieira, E. M. F; Rodrigues, J. A.; Maciel, Marino Jesus Correia; Correia, J. H.[Excerpt] MEMS-based atomic vapor cells have a wide range of applications, as they can be miniaturized for chip-scale atomic clocks, atomic gyroscopes and atomic magnetometers. Current available techniques for imaging and registering the human brain activity are based on superconducting quantum interference devices (SQUIDs) that require the use of liquid helium at 4 K to reach the desired levels of sensitivity.
Radiotherapy-customized head immobilization masks: from modeling and analysis t...
Loja, Amélia; Craveiro, D. S.; Vieira, Lina Oliveira; Sousa, Eva; Rodrigues, J. A.; Portal, R. J. F.Immobilization devices may be a valuable aid to ensure the improved effectiveness of radiotherapy treatments where constraining the movements of specific anatomical segments is crucial. This need is also present in other situations, specifically when the superposition of various medical images is required for fine identification and characterization of some pathologies. Because of their structural characteristi...
Radiotherapy-customized head immobilization masks: from modeling and analysis t...
Loja, M. A. R.; Craveiro, D. S.; Vieira, Lina; Sousa, Eva; Rodrigues, J. A.; Portal, R. J.Immobilization devices may be a valuable aid to ensure the improved effectiveness of radiotherapy treatments were constraining the movements of specific anatomical segments is crucial. This need is also present in other situations, specifically when the superposition of various medical images is required for fine identification and characterization of some pathologies. Because of their structural characteristic...
Photodynamic therapy at low-light fluence rate: "in vitro" assays on colon canc...
Rodrigues, J. A.; Amorim, Ricardo; Silva, M. F.; Baltazar, Fátima; Wolffenbuttel, R. F.; Correia, J. H.This paper presents the results of in vitro photodynamic therapy assays on RKO and HCT-15 cell lines. The envisaged implementation is in autonomous medical microdevices, such as endoscopic capsules for clinical treatment of several types of gastrointestinal tract tumors. Because of their very limited device volume, light fluence and fluence rate needed to destroy tumor cells should be minimized. Foscan or meta-...
Developments on finite element methods for medical image supported diagnostics
Almeida, Ana; Barbosa, J. I.; Carvalho, A.; Loja, M. A. R.; Portal, R.; Rodrigues, J. A.; Vieira, LinaVariational image-processing models offer high-quality processing capabilities for imaging. They have been widely developed and used in the last two decades, enriching the fields of mathematics as well as information science. Mathematically, several tools are needed: energy optimization, regularization, partial differential equations, level set functions, and numerical algorithms. For this work we consider a se...
Interpretation of medical images: end of subjectivity?
Almeida, Ana; Vieira, Lina; Figueiredo, Sérgio; Rodrigues, J. A.The aim of the study: To describe the importance of blood smears images, and the renal scintigraphy, in clinical diagnosis and to describe the relevant aspects that must be analyzed in such images, taking into account the reduction of the subjectivity and variability in the interpretation of the findings. Final considerations: Interpretation of either blood smears or renal scintigraphy is associated with traini...
Imobilização da região da cabeça por prototipagem rápida para fins de diagnósti...
Craveiro, D. S.; Loja, M. A.; Vieira, Lina; Sousa, Eva; Costa, Durval C.; Parafita, Rui; Rodrigues, J. A.Objetivo do estudo: Modelar e testar, por procedimentos de prototipagem rápida, máscaras de imobilização da cabeça através da imagem médica. Conclusões: Dispositivos de imobilização construídos por prototipagem rápida têm características favoráveis para aplicação em imobilização em diagnóstico e terapia. Para dispositivos de imobilização da cabeça as diferenças encontradas na análise estática realizada foram mí...
Análise de imagens de cintigrafia renal com um método de elementos finitos
Vieira, Lina; Rodrigues, J. A.Objetivo do estudo: Avaliar a reprodutibilidade de um método variacional, discretizado por um método de elementos finitos, na análise de imagens de cintigrafia renal. Conclusões: A metodologia apresentada permite de forma automática obter resultados idênticos aos métodos tradicionais quanto à captação relativa renal, forma e ao número de pixeis.